双馈感应风电机组参与系统调频的控制策略研究

发布时间：2018-01-11 05:19

本文关键词：双馈感应风电机组参与系统调频的控制策略研究　出处：《华北电力大学》2014年硕士论文　论文类型：学位论文

【摘要】：风力发电作为绿色可再生能源近年来在我国快速发展，风电在电网中的比例也不断提高，使风电场像常规电厂一样承担电网的调频任务成为了新要求。在各个风电场中，双馈感应风电机组因变速运行且控制特性灵活，已成为主流机型。本文就双馈风电机组参与系统频率调节的问题进行研究，并取得了以下成果：（1）建立了风力机和双馈电机的数学模型，研究了该机组的工作原理和功率流动关系，提出了转子侧变流器与网侧变流器的矢量定向控制策略，并分析了双馈机组的最大功率追踪过程，为机组频率策略的研究提供了理论基础。（2）在双馈机组变速运行以追踪最大功率的模式下，研究了双馈风电机组对系统频率变化的响应特性；阐述了大规模风电并网对系统整体转动惯量和其一次调频能力的影响，以及风电渗透率不断提高后系统频率的波动结果。为了双馈机组频率策略的研究，还介绍了同步机组的惯性响应和一次调频过程。（3）分析了系统频率波动时双馈机组的功率控制能力，给出了风电机组输出功率随转子转速变化的规律，从而表明双馈风电机组具有参与系统频率调节的潜在能力。此外，还针对风力机转速的不同响应程度提出了变速风电机组虚拟转动惯量的概念，并推导出了其具体的数学表达式。（4）基于双馈机组的功率追踪过程，提出了双馈风电机组的两种频率响应策略。通过双馈机组功率追踪曲线的切换，，实现了双馈风机的惯性响应控制；通过双馈机组载荷度的变化，实现了双馈风机的一次频率控制，并阐述了两种频率控制策略的具体方式和详细过程。（5）在Matlab/Simulink仿真软件中建立了电力系统的仿真模型，对本文所述的双馈机组频率控制策略进行了仿真分析，结果表明双馈机组具有良好的频率响应特性，与同步发电机组一样可对系统频率提供动态支持，即验证了本文所提控制方案的有效性。
[Abstract]:Wind power, as a green renewable energy, has been developing rapidly in China in recent years, and the proportion of wind power in power grid is also increasing. It is a new requirement for wind farms to take on the frequency modulation tasks of power grid like conventional power plants. In each wind farm, the doubly-fed induction wind turbines operate flexibly because of the variable speed and the control characteristics are flexible. In this paper, the problem of doubly-fed wind turbine participating in the frequency regulation of the system has been studied, and the following results have been achieved: 1) the mathematical models of wind turbine and doubly-fed generator are established, the working principle and power flow relationship of the unit are studied, and the vector oriented control strategy of rotor side converter and grid side converter is proposed. The maximum power tracking process of doubly-fed generator is analyzed, which provides a theoretical basis for the research of frequency strategy. 2) the response characteristics of doubly-fed wind turbine to the frequency change of the system are studied in the mode of variable speed operation of doubly-fed unit to track the maximum power. The influence of large-scale wind power grid connection on the overall rotational inertia and its primary frequency modulation ability of the system, as well as the frequency fluctuation results of the system after the increase of wind power permeability, are described in order to study the frequency strategy of doubly-fed generating units. The inertial response and the primary frequency modulation process of the synchronous unit are also introduced. The power control ability of the doubly-fed generator is analyzed when the frequency of the system is fluctuating, and the variation of the output power of the wind turbine with the rotor speed is given. It shows that the doubly-fed wind turbine has the potential ability to participate in the frequency regulation of the system. In addition, the concept of virtual moment of inertia of the variable speed wind turbine is put forward according to the different response degree of the speed of the wind turbine. The mathematical expressions are derived. Based on the power tracing process of doubly-fed wind turbine, two frequency response strategies of doubly-fed wind turbine are proposed. The inertial response control of doubly-fed fan is realized by switching the power tracing curve of doubly-fed wind turbine. The primary frequency control of the doubly-fed fan is realized by changing the load degree of the doubly-fed fan. The specific ways and the detailed process of the two kinds of frequency control strategies are described. 5) the simulation model of power system is established in the Matlab/Simulink simulation software, and the frequency control strategy of doubly-fed generator is simulated and analyzed. The results show that the doubly-fed generator unit has good frequency response characteristics and can provide dynamic support to the system frequency just as the synchronous generator set does. That is to say, the effectiveness of the control scheme proposed in this paper is verified.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614

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